A separate product, not a variant
The isophthalic SMC and DMC resins share one catalogue specification. The terephthalic pair do not. SPR 401 DMC has its own values: viscosity 1,200–2,200 cPs at 25 °C against 800–1,500 cPs for SPR 401 SMC, and an ambient gel time of 14–22 minutes against that grade’s 12–18 minutes. The catalogue lists them as separate products.
Its reference QC cure also differs slightly: MEKP 1.5% with cobalt octoate 0.5%, each added separately, where the SMC resin is referenced at 0.4% cobalt.
What higher viscosity means for a dough
In a dough compound the resin has to carry a heavy filler loading and bind short fibre into a mass that can be weighed, handled and pressed. The resin’s viscosity is one of the levers the compounder uses to set the dough’s body and flow. A more viscous base resin changes how the dough mixes and how it moves into the tool.
Whether that suits a given compound is the compounder’s judgement, confirmed by mixing and moulding trials.
Complex moulded parts
The catalogue lists dough moulding compound production, compression-moulded composite components and complex moulded FRP parts. Complex parts — ribs, bosses, thin walls next to thick sections, moulded-in inserts — test how a dough fills the cavity and knits where flow fronts meet. Those details should come with the enquiry.
Terephthalic family context
Terephthalic resins are built on terephthalic acid, the para isomer of the phthalic acids. The catalogue positions its terephthalic moulding-compound resins for heat and chemical resistance and mechanical performance in qualitative terms; no numerical moulded-part values are published for SPR 401 DMC.